The present invention relates generally to thermal insulation systems for piping, and more particularly to a factory jacketed thermal pipe insulation having relief cuts therein to compensate for fluctuations in form resulting from varying environmental factors.
Pipes that convey liquid or gaseous materials from one point to another often require insulation and protection from environmental elements such as heat and cold. Insulation is especially important in industrial and critical process applications. To protect against the elements, one option has been to provide piping with the insulation already installed thereon. Thus, piping and insulation are made available as a combined unit. The purchase of the pipe and insulation as a combined unit ensures that the insulation will fit the pipe perfectly. However, when the pipe needs repair or maintenance, the process of removing and replacing the insulation is difficult and time consuming.
To simplify the insulation process, a factory jacketed insulation system is available, separately from the pipes. The factory jacketed insulation system allows the user the option of the installation of a wider variety of piping of various construction and materials without the necessity of purchasing the piping and insulation as a combined unit. The factory jacketed insulation system includes a first semi-circular section that is dimensioned to mate with a second semi-circular section. The two semi-circular sections are permanently bonded to a single exterior jacket to complete the insulation system. The first and second sections have corresponding notches at the ends for easy fit and mating. The factory jacketed insulation system can be installed by simply pressing the first semi-circular section around half of the pipe and wrapping the second section over the remaining pipe thereby joining the first and second sections together. The factory-applied jacket allows for precision mating of the two insulation sections. There is no need to remove the pipe when installing the insulation. Furthermore, the pipe and the insulation need not be purchased together as a combined unit. The slide-over arrangement also allows for simplified testing of the installation for leakage and repair of the pipes.
The disadvantage of the factory jacketed insulation system is that the insulation material is sensitive to the moisture content in the ambient air. In a dry environment, the insulation material is at its smallest condition. When the humidity rises, the insulation material expands. A 30% rise in humidity could result in a 3% increase in the size of the material. The fluctuation in the size of the insulation material interferes with the fit around the pipe. The problem is magnified for larger pipes since there is an increase in the surface area.
This problem is illustrated in the manufacturing/sale scenario. The manufacturer, located in a first city, cuts the insulation to the customer""s specifications. The insulation is then shipped to a second city having a different ambient air moisture level than the first city. When the insulation arrives at the second city, it will have fluctuated in size and will no longer fit around the pipe. The unsatisfied customer will undoubtedly complain to the manufacturer and return the insulation for evaluation. Upon arrival in the first city, the insulation will return to its original size, evading a negative analysis. The manufacturer is not able to respond to the customer""s complaint.
The problem can arise even if the insulation is not shipped to another city. For instance, insulation that is cut in humid temperatures is swollen and contains water. Once the insulation is placed on a hot pipe, the water evaporates causing the insulation to shrink. If a jacket is placed around the insulation, the contraction of the insulation will cause the jacket to wrinkle.
Accordingly, there is a need for a thermal insulation system that is easy to install and accommodates fluctuation in size of the insulation resulting from changes in temperature and humidity.
The thermal insulation system of the present invention includes an upper insulation member engageable with a lower insulation member to collectively surround and insulate a pipe. The ends of the upper and lower insulation members are preferably configured to form shiplap joints when the insulation members are wrapped around the pipe and connected together. In a preferred embodiment, the first end of the upper insulation member preferably has a projection that is dimensioned to fit into a groove in the first end of the lower insulation member to form a shiplap joint. Similarly, the second end of the lower insulation member has a projection that is dimensioned to fit into a groove in the second end of the upper insulation member forming a second shiplap joint. The projections on the first end of the upper insulation member and the second end of the lower insulation member preferably have a dome-shaped cross-section and extend across the entire length of the upper and lower insulation members. Correspondingly, the grooves in the second end of the upper insulation member and in the first end of the lower insulation member have a dome-shaped cross section to accommodate the respective projections.
The upper and lower insulation members are preferably made of a flexible foam material and, more preferably, made of TECHLITE(copyright), an open melamine foam. Foam material tends to fluctuate in size and shape depending on the environmental conditions. To compensate for the fluctuations in size and shape, relief cuts are made in the foam material to minimize the variance in the insulation. Specifically, a series of constant radius relief cuts are provided on the first and second ends of each of the insulation members. The cuts preferably extend from the ends of the insulation members toward the center portion. In a preferred embodiment, the radius of each of the cuts remains constant.
In addition to the constant radius relief cuts, radial relief cuts are made on the inner surface of the upper and lower insulation members. The cuts extend axially along the length of insulation members and radially advance from the inner surface toward the outer surface of each of the insulation members. In a preferred embodiment, three radial relief cuts are provided on each of the upper and lower insulation members. On each insulation member, one radial relief cut is preferably positioned at the center of the insulation member and the second and third radial relief cuts are provided on either side of the first radial relief cut, equidistant therefrom.
In a preferred embodiment of the present invention, the upper and lower insulation members are arc-shaped and the inner surface of the insulation members have variable radii of curvature. The radius of curvature at the center of the insulation members is preferably greater than the radius of curvature at the first and second ends of the insulation members such that a gap is created between the inner surface and the pipe at the center portion of each of the insulation member. The gap accommodates the variation in the size and shape of the insulation members resulting from varying environmental conditions. The various forms of relief cuts and gaps that accommodate size fluctuations allow the foam material of the insulation members to fluctuate while still preserving the connection at the shiplap joints of the insulation members and maintaining the fit of the insulation members around the pipe.
This invention, together with the additional features and advantages thereof, which was only summarized in the foregoing passages, will become more apparent to those of skill in the art upon reading the description of the preferred embodiments, which follows in the specification, taken together with the following drawings.